Do keto diets actually work? Fats have higher calories than carbs and I heard that low carb diets were unhealthy.

They can work - they do force your body to burn fats preferentially as opposed to carbs. The problem is that your body (specifically, your brain) does need glucose to operate, so you have to watch your intake, lest you get your body having to convert lots of fats/proteins into carbs, which has certain unpleasant metabolic byproducts (ketones/ammonia). Your body's normally able to handle these byproducts, but it does merit monitoring if you go that route.

Basically, the theory's sound, but the application often requires lots of trial and error for each individual. As Mister mentioned with regard to calories, you may not actually know what your body needs nutritionally. So if you're smart about it, it can work.

They can work - they do force your body to burn fats preferentially as opposed to carbs. The problem is that your body (specifically, your brain) does need glucose to operate, so you have to watch your intake, lest you get your body having to convert lots of fats/proteins into carbs, which has certain unpleasant metabolic byproducts (ketones/ammonia). Your body's normally able to handle these byproducts, but it does merit monitoring if you go that route.

Ketones aren't an unpleasant metabolic byproduct, they're the goal of the diet - glucose is one fuel the body can use, ketones are the other. Glucose is not a requirement.

At the age of 47, I feel awesome on a ketonic diet. I've lost fat, have high energy levels, no insulin crash after a meal, joint pains (fingers, hips and knees) have disappeared, and most importantly for me, so has my asthma.

Ketones aren't an unpleasant metabolic byproduct, they're the goal of the diet - glucose is one fuel the body can use, ketones are the other. Glucose is not a requirement.

At the age of 47, I feel awesome on a ketonic diet. I've lost fat, have high energy levels, no insulin crash after a meal, joint pains (fingers, hips and knees) have disappeared, and most importantly for me, so has my asthma.

Of course, YMMV, but it definitely works for me.

Two of the three ketone bodies typically created in fatty acid metabolism are used as fuel, yes - the other is acetone, which is a waste product. Disposing of said waste product is usually the main point of concern here, but again, the body's usually capable of handling it.

Chili Pepper essentially pointed that out. I'm aware that fatty acid catabolism supplies a large percentage of the body's energy needs, but I was under the impression (based on previous study) that certain operations require glucose exclusively, whether brought in directly or derived via gluconeogenesis from a different compound. I may be dead wrong, but that's how I've learned it and how I've seen it presented in texts and research on the subject. Always open to new evidence, though!

Chili Pepper essentially pointed that out. I'm aware that fatty acid catabolism supplies a large percentage of the body's energy needs, but I was under the impression (based on previous study) that certain operations require glucose exclusively, whether brought in directly or derived via gluconeogenesis from a different compound. I may be dead wrong, but that's how I've learned it and how I've seen it presented in texts and research on the subject. Always open to new evidence, though!

Outside of the initial hardcore period where you cut out carbs as much as possible (to exhaust the body's store of glycogen, and make it scramble for an alternative fuel source), keto calls for low carbs, not no carbs. So, there's still some glucose available.

You sound like you're far better educated on the biochemistry in general, so I'm not going to push my luck ;)

I'd assume you'd have to eat multiple times a day (like a bodybuilder) so that your metabolism is up

Eating more frequently doesn't change your metabolism. Not directly anyway. If you eat more frequently you can train yourself to eat more over all, and feel hungry more quickly, which I suppose is a kind of change.

Eating more frequently doesn't change your metabolism. Not directly anyway. If you eat more frequently you can train yourself to eat more over all, and feel hungry more quickly, which I suppose is a kind of change.

Really? I read on bodybuilding.com that your metabolism is higher for a few hours after you eat which is why the bodybuilders eat throughout the day.

Outside of the initial hardcore period where you cut out carbs as much as possible (to exhaust the body's store of glycogen, and make it scramble for an alternative fuel source), keto calls for low carbs, not no carbs. So, there's still some glucose available.

You sound like you're far better educated on the biochemistry in general, so I'm not going to push my luck ;)

That's kind of what I figured; the only times I've heard of people going absolutely zero-carbs is in cases of extreme (and incorrect) interpretation of Atkins and similar diets. Nutritionists I've studied with affectionately refer to such diets as "suicide diets". ;P

Ha! I'm just glad I remember all this stuff - it's been a while since I've had to use it. Sounds like you get the ideas behind the diet, though, and it definitely sounds like it's working for you, which...is kinda the idea, after all. ; )

Originally Posted by Cuddles

Now I have a question.

Carbs are sugar basically. Just chains of them, correct? (like how amino acid chains are proteins)

Couldn't you technically cut out carbs and instead have low/moderate-sugar, high-fat, high-protein diet? Of course, with all of the essential vitamins and minerals as well.

In this type of diet, I'd assume you'd have to eat multiple times a day (like a bodybuilder) so that your metabolism is up and your body has a constant supply of energy (some amounts of sugar, fats).

Am I correct?

Technically, "carbohydrate" just means a compound made only of carbon, oxygen, and hydrogen. But you're right in that, when people talk about "carbs", they're usually referring to long chains of these molecules, like glucose (which is your standard 6-carbon carbohydrate). But if you had a glucose molecule by itself, you'd have what's called a "simple" sugar, which we typically just call "sugar".

So, technically, you can't "cut out carbs" and still have sugar - they're the same thing, one's just longer than the other. What that means is it generally takes longer to digest. And CrackFox is right: More frequent meals won't up your metabolism by itself, as far as I'm aware. Part of the reason to eat more frequently is to regulate/control your intake better, and to keep from getting the peaks and valleys from insulin response. Getting your metabolism up is much more closely related to demand placed on the body - digestion hopefully isn't all that stressful, so it doesn't make a huge difference when we're talking gross basal metabolic rate.

Again, I'm hardly an expert - this is all just from my studies and research. If anybody's got evidence/experience to the contrary, I'd love to hear it.